FA stands for farnesoic acid, and I've been running it in the lab to make sure that what I'm looking at in my snow crab hemolymph truly is methyl farnesoate (MF) and not FA. (Remember, MF is a crustacean reproductive hormone. I'm hoping to quantify levels of MF in various groups of snow crab males to see how the terminal molt affects their reproductive physiology.)
FA is the precursor to MF. See how similar they look?
two sesquiterpenoids: MF (top) and FA (bottom)
see how they compare to the insect juvenile hormone III here
For more fun, long, sciencey words: MF comes from FA through the methylation of the latter, which is catalyzed by farnesoic acid O-methyltransferase (FAMeT)! Thrilling I know.
The good news is, after running different levels of FA through the HPLC, I am ever the more confident in my MF results! Yay for anagrams, and yay for me!